Adds north symbols (18 options) and scale bars in kilometers to maps in geographic or metric coordinates created with 'ggplot2' or 'ggmap'.
New arguments in scalebar function to control the scale bar position when faceting. It is possible to place the scale bar just in one facet.
broom package suggested for function's examples.
maptools replaced by rgdal for shapfiles reading.
Functions from grid package are selectively imported.
Examples changed to avoid the use of the rgdal package (currently, some users might get "WARNING: no proj_defs.dat in PROJ.4 shared files", using this package).
'ggplot2' includaded as a loaded dependency (previoulsy just imported).
'plot' and 'rasterImage' functions imported from graphics.
function 'symbols' renamed as 'northSymbols' to avoid masking.
function 'theme_bln' renamed as 'blank'.